Retro guidewire reamer

ABSTRACT

A retro guidewire reamer includes a cutting member, and a mechanism for moving the cutting member from a closed position to a deployed position in a single manual motion. Once a desired size of a bone tunnel is established, a surgeon uses the reamer to create a primary bone tunnel over a guidewire from the outside in. The surgeon retracts the guidewire, and activates the mechanism to deploy the cutting member within the bone joint to conform to the size of a tendon graft. The surgeon uses the deployed cutting member to create a counter bore through the bone in a retrograde manner. Once the counter bore is drilled, the surgeon activates the mechanism to close the cutting member, allowing the reamer to be withdrawn through the primary tunnel. The retro guidewire reamer can be used to provide more accurate bone tunnel placement during ligament reconstruction surgery.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a division of co-pending U.S. patent applicationSer. No. 14/198,900 filed Mar. 6, 2014, entitled RETRO GUIDEWIRE REAMER,which in turn claims benefit of the priority of U.S. Provisional PatentApplication No. 61/776,896 filed Mar. 12, 2013, U.S. Provisional PatentApplication No. 61/805,578 filed Mar. 27, 2013, and U.S. ProvisionalPatent Application No. 61/858,800 filed Jul. 26, 2013, the contents ofwhich are incorporated by reference herein in their entirety for allpurposes.

TECHNICAL FIELD

The present application relates generally to surgical apparatus andmethods, and more specifically to surgical apparatus and methods ofcreating tunnels through bone tissue during arthroscopic ligamentreconstruction surgery.

BACKGROUND

Desired outcomes for arthroscopic ligament reconstruction surgery aregenerally achieved by establishing the proper shape and placement oftorn tissue. In a typical arthroscopic procedure, however, a cruciatefootprint is often hidden from view by soft tissue, as well as remnantcruciate tissue. Such an arthroscopic procedure typically includesdebriding the soft tissue and/or the remnant cruciate tissue tovisualize the repair site, and establishing approach angles throughportals located on the patient's skin. The reconstruction can then beaccomplished by creating bone tunnels through the patient's femur andtibia. These bone tunnels are subsequently filled with a tendon graft,replicating the original damaged tissue.

The typical arthroscopic procedure described above has shortcomings,however, due at least in part to problems pertaining to the lack ofvisualization, the approach angles, and the shape of the tendon graft.Although the shape of the tendon graft is generally not round, that isoften the shape of the reconstructed repair. Because the approach anglesare generally not perpendicular to the skin surface, however, theportals located on the patient's skin are often visualized as beingelliptical, making proper placement of the bone tunnels through thepatient's femur and/or tibia difficult to achieve.

While performing arthroscopic ligament reconstruction surgery, a surgeontypically makes a small incision in a patient's skin covering thesurgical site, e.g., a bone joint, to allow a surgical instrument(s) tobe placed in the bone joint and manipulated through arthroscopicvisualization. One such surgical instrument can be configured to operatein both a drilling mode and a cutting mode. The surgical instrumentincludes a shaft, and a drill bit portion having a conical, multi-bladeconfiguration. The drill bit portion is configured to engage with theshaft, and to articulate between a “straight” position approximatelyparallel to the longitudinal axis of the shaft, and a “flip”non-parallel position relative to the longitudinal axis of the shaft.While operating in the drilling mode, the surgical instrument can beemployed in an antegrade manner with the conical, multi-blade drill bitportion in the straight parallel position relative to the shaft'slongitudinal axis. While operating in the cutting mode, the surgicalinstrument can be employed in a retrograde manner with the conical,multi-blade drill bit portion in the flip non-parallel position relativeto the shafts longitudinal axis.

For torn knee anterior cruciate ligament (ACL) reconstruction, there hasbeen an evolution in the anatomic femoral placement at the reconstructedACL. One approach to achieving proper placement of the reconstructed ACLincludes creating a tunnel from the outside to the inside (i.e., fromthe “outside in”) of the patent's femur. With this approach, a guide canbe used to establish a desired path for the femoral tunnel, and aguidewire can be placed along the desired path. A trans-tibial approachmay then be employed, in which the knee is flexed to about 90°, theguide is placed in the center of the tibial footprint, and a tunnel isdrilled through the tibia and extending into the femur. Alternatively, aflexible and/or retrograde drill may be employed, or the patient's kneemay be hyper-flexed to allow the femoral and tibial tunnels to bedrilled independent of one another.

Still another approach may be employed, in which the femoral/tibialtunnels are drilled through an anterior medial portal. With thisapproach, a curved guide can be used to place a guidewire, and anappropriately sized reamer can be advanced over the guidewire to createa bone tunnel. Alternatively, the patient's knee can be hyper-flexed toallow straight line drilling of the bone tunnel. A retro-drill can alsobe assembled inside the bone joint, and the bone tunnel can then bedrilled in a retrograde manner.

SUMMARY

In accordance with the present application, surgical instruments andmethods of using such surgical instruments (also referred to herein asa/the, “retro guidewire reamer(s)”) are disclosed. In a first aspect, aretro guidewire reamer includes at least one cutting member, and amechanism operative to move the cutting member, by remote activation,from a closed position to an opened or deployed position and vice versa,thereby allowing for the creation a counter bore through bone tissue(e.g., a tibia, a femur). In an exemplary mode of operation, a surgeonestablishes a path through the bone for a guidewire using a guide,places the guidewire along the path, and removes the guide. The surgeonthen establishes the proper size of a bone tunnel to best fit areplacement tendon graft. Once the proper size of the bone tunnel isestablished, the surgeon uses the retro guidewire reamer with anappropriately sized drill bit to create a primary bone tunnel over, theguidewire from the outside in. Once the primary bone tunnel is drilled,the surgeon retracts the guidewire, and activates the mechanism to openor deploy the cutting member within the bone joint to conform to theestablished size of the bone tunnel for the replacement tendon graft.The surgeon then uses the retro guidewire reamer with the opened ordeployed cutting member to create a counter bore through the bone in aretrograde manner. Once the counter bore is drilled, the surgeonactivates the mechanism to close the cutting member, allowing the retroguidewire reamer to be withdrawn through the primary bone tunnel createdby the drill bit.

In a second aspect, a retro guidewire reamer includes a tubular shafthaving a distal end, at least one cutting member disposed adjacent thedistal end of the tubular shaft, and a first mechanism operative to movethe cutting member from a closed position to an opened or deployedposition. The tubular shaft is configured to be disposed over aguidewire, which can have at least one helix spline, flute, slot,thread, or any other suitable structural feature formed on a surfacethereof. The cutting member includes at least one tab adapted to engagewith the structural feature of the guidewire while the cutting member isdisposed in the opened or deployed position, thereby securing thecutting member in the opened or deployed position. The retro guidewirereamer further includes a second mechanism operative to secure theguidewire within the tubular shaft while the cutting member is disposedin the opened or deployed position.

In a third aspect, a retro guidewire reamer includes a drill bit havinga cannulated shaft with a longitudinal axis, and a cutting memberconfigured as a small hollow segment with a central axis. The cuttingmember is pivotally, rotatably, or otherwise movably coupled at a distalend of the cannulated shaft such that it can pivot, rotate, or otherwisemove between a first position where its central axis is coincident withthe longitudinal axis of the shaft, and a second position where itscentral axis is disposed at an angle to the longitudinal axis of theshaft. The cutting member has a cannulated sidewall with sharpened edgesat a forward circumferential end thereof, as well as sharpened edges onan outside surface thereof.

In a fourth aspect, a retro guidewire reamer includes a drill bit havinga cannulated shaft with a longitudinal axis, and a cutting memberconfigured as a small hollow segment with a central axis. The cuttingmember is pivotally, rotatably, or otherwise movably coupled adjacent adistal end of the cumulated shaft such that it can pivot, rotate, orotherwise move between a first position where its central axis iscoincident with the longitudinal axis of the shaft, and a secondposition where its central axis is disposed at an angle to thelongitudinal axis of the shaft. The cannulated shaft has sharpened edgesat a forward circumferential end thereof, and the cutting member has asidewall with sharpened edges on an outside surface thereof.

In a further exemplary mode of operation, a surgeon establishes a paththrough bone tissue for a guidewire using a guide, places the guidewirealong the path, and then removes the guide. With the drill bit'scannulated shaft and cutting member in the first position (where itscentral axis is coincident with the longitudinal axis of the shaft)placed over the guidewire, the surgeon uses the retro guidewire reamerto drill a tunnel through the bone over the guidewire, from the outsidein, in an antegrade manner. In accordance with the third aspect of theretro guidewire reamer described herein, the surgeon drills the bonetunnel using the sharpened edges at the forward circumferential end ofthe cutting member, in accordance with the fourth aspect of the retroguidewire reamer described herein, the surgeon drills the bone tunnelusing the sharpened edges at the forward circumferential end of thecannulated shaft. Next, the surgeon retracts the guidewire to allow thecutting member to pivot, rotate, or otherwise move from the firstposition to the second position (where its central axis is disposed atan angle to the shaft's longitudinal axis). The surgeon then advancesthe guidewire and locks it to the cannulated shaft, for example, using alock screw, thereby securing the cutting member in the angled secondposition. With the cannulated shaft paced over the guidewire and thecutting member in the second position, the surgeon drills a counter borethrough the bone over the guidewire in a retrograde manner, using thesharpened edges on the outside surface of the cutting member's sidewall.

Using the disclosed retro guidewire reamers, a surgeon canadvantageously deploy a cutting member within a bone joint with a singlemanual motion. Further, because the cutting member can be deployedwithin the bone joint by remote activation, the amount of bone jointspace required for successful deployment of the cutting member isreduced. Moreover, by providing retro guidewire reamers that include adrill bit having a cannulated shaft, and a cutting member pivotally,rotatably, or otherwise movably coupled to the cannulated shaft andadapted to engage a guidewire at least while in an opened or deployedposition, the retro guidewire reamers can be advantageously used with aguidewire for more accurate bone tunnel placement during arthroscopicligament reconstruction surgery, such as ACL reconstruction surgery.

Other features, functions, and aspects of the invention will be evidentfrom the Detailed Description that follows:

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated in and constitute apart of this specification, illustrate one or more embodiments describedherein and, together with the Detailed Description, explain theseembodiments. In the drawings:

FIGS. 1-5 b illustrate an exemplary mode of operating exemplary retroguidewire reamer, in accordance with the present application;

FIGS. 6a and 6b illustrate the retro guidewire reamer employed in themode of operation illustrated in FIGS. 1-5 b;

FIG. 7 illustrates various components included in the retro guidewirereamer of FIGS. 6a and 6 b;

FIGS. 8a-8c illustrate an exemplary distal tip of the retro guidewirereamer of FIGS. 6a and 6 b;

FIGS. 9a and 9b illustrate an exemplary mechanism or deploying a cuttingmember included in the retro guidewire reamer of FIGS. 6a and 6 b;

FIGS. 10a-12b illustrate various as relating to the operation of themechanism of FIGS. 9a and 9 b;

FIGS. 13a -16 illustrate various aspects relating to the operation andassembly of the retro guidewire reamer of FIGS. 6a and 6 b;

FIGS. 17a-19b illustrate a first alternative embodiment of the retroguidewire reamer of FIGS. 6a and 6 b;

FIGS. 20a and 20b illustrate a second alternative embodiment of theretro guidewire reamer of FIGS. 6a and 6 b;

FIGS. 21a and 21b illustrate various components included in the retroguidewire reamer of FIGS. 20a and 20 b;

FIGS. 22a-22c illustrate additional views of the retro guidewire reamerof FIGS. 20a and 20 b, including an exemplary retro lock knob, anexemplary retro lock bushing ring, and an exemplary retro drive bushing;

FIGS. 22d-22f illustrate are exemplary distal tip of the retro guidewirereamer of FIGS. 20a and 20 b;

FIGS. 23a-23m illustrate an exemplary mode of operating the retroguidewire reamer of FIGS. 20a and 20 b;

FIG. 24 illustrates a third alternative embodiment of the retroguidewire reamer of FIGS. 6a and 6 b;

FIG. 25 illustrates a detailed view of the retro guidewire reamer ofFIG. 24 in a configuration for drilling a tunnel through bone tissueover a guidewire in an antegrade manner;

FIG. 26 illustrates a detailed view of the retro guidewire reamer ofFIG. 24 in a configuration for drilling a counter bore through bonetissue over a guidewire in a retrograde manner;

FIGS. 27-31 illustrate an exemplary use of the retro guidewire reamer ofFIG. 24 for creating a tunnel and a counter bore through femoral bonetissue;

FIG. 32 illustrates an alternative embodiment of the retro guidewirereamer of FIG. 24; and

FIG. 33 is a flow diagram illustrating an exemplary method of operatingthe retro guidewire reamer of FIG. 24.

DETAILED DESCRIPTION

The disclosures of U.S. Provisional Patent Application No. 61/776,896filed Mar. 12, 2013 entitled RETRO GUIDEWIRE REAMER, U.S. ProvisionalPatent Application No. 61/806,578 filed Mar. 27, 2013 entitled RETROGUIDEWIRE REAMER, and U.S. Provisional Patent Application No. 61/858,800filed Jul. 26, 2013 entitled RETRO GUIDEWIRE LOCK REAMER, are herebyincorporated herein by reference in their entirety.

An exemplary mode of operating an illustrative embodiment of a retroguidewire reamer 1100 is described below with reference to FIGS. 1-5 b,in accordance with the present application. As shown in FIG. 1, asurgeon establishes a desired path for a guidewire 1114 through femoralbone 1116. For example, the desired path may be established using aguide (not shown), such as a pinpoint guide or any other suitable guide.The surgeon places the guidewire 1114 along the desired path, andremoves the guide. The surgeon can then determine the size of a primarybone tunnel 1112 (see FIG. 4), as well as the size of a counter bore1110 (see FIG. 4) through the femoral bone 1116 appropriate to fit areplacement tendon graft, using any suitable technique known in the art.As shown in FIGS. 2a and 2 b, using a drill bit 1102 appropriately sizedto create the primary bone tunnel 1112 (e.g., the drill bit 1102 can bea 4.5 mm drill bit or any other suitable drill bit), the surgeon can usea power drill (not shown) to drill the primary bone tunnel 1112 throughthe femoral bone 1116 over the guidewire 1114 from the outside in. Asshown in FIGS. 3a and 3 b, the surgeon then at least partially retractsthe guidewire 1114 and uses a mechanism 1106 to manually open deploy atleast one cutting member 1108 (e.g., 1 or 2 such cutting members) withina bone joint 1117 (see also FIG. 1). In one embodiment, the surgeon canpush or slide an outer tubular shaft 1104 toward the mechanism 1106 inthe direction indicated by a directional arrow 1120 (see FIG. 3a ),thereby causing the mechanism 1106 to open or deploy the cutting member1108 within the bone joint 1117 in a single manual motion. As shown inFIG. 4, the surgeon then uses the power drill with the deployed cuttingmember 1108 to create the counter bore 1110 through the femoral bone1116 in a retrograde manner. Once the counter bore 1110 is drilled, thesurgeon activates the mechanism 1106 to close the cutting member 1108,allowing the retro guidewire reamer 1100 to be withdrawn through theprimary bone tunnel 1112 created by the drill bit 1102 (see FIGS. 5a and5b ).

It is noted that, in the exemplary mode of operation described above,the counter bore 1110 may be drilled along the axis of the primary bonetunnel 1112, or at a predetermined angle to the primary bone tunnelaxis. It is further noted that the retro guidewire reamer 1100 can becannulated to allow fluid to pass through the tubular shaft during use,thereby clearing out any soft tissue that may potentially block thedeployment of the cutting member 1108 within the bone joint 1117.

FIG. 6a depicts a side view of the retro guidewire reamer 1100, as wellas a detailed view of the drill bit 1102 and the outer tubular shaft1104 disposed over the guidewire 1114. FIG. 6b depicts a further sideview of the retro guidewire reamer 1100, as well as a detailed view ofthe drill bit 1102, a tubular shaft 1103, and the cutting, member 1108in its fully opened or deployed position. As shown in FIGS. 6a and 6 b,the retro guidewire reamer 1100 includes the drill bit 1102 having thetubular (cannulated) shaft 1103, the cutting member 1108 operativelycoupled near a distal end of the tubular shaft 1103, the elongated outertubular shaft 1104, and the mechanism 1106 for manually opening ordeploying the cutting member 1108. As discussed herein, the retroguidewire reamer 1100 can be advantageously used with the guidewire 1114(e.g., a 2.4 mm guidewire, or any other suitable guidewire or guide pin)for more accurate bone tunnel placement during arthroscopic ligamentreconstruction surgery, such as anterior cruciate ligament (ACL)reconstruction surgery.

FIG. 7 depicts various components of the retro guidewire reamer 100,including the drill bit 1102, the tubular shaft 1103, the cutting member1108, the outer tubular shaft 1104, and the mechanism 1106 for manuallyopening or deploying the cutting member 1108. FIG. 7 further depicts anactuator 1130, at least one tab 1136 located at a proximal end of thetubular shaft 1104, a compression spring 1138, a cam wheel 1140, atleast one drive link 1142, and a bushing 1144, all of which are furtherdescribed below.

FIG. 8a depicts another detailed view of the drill bit 1102, the tubularshaft 1103, the outer tubular shaft 1104, and the cutting member 1108 inits fully opened or deployed position. FIG. 8a further depicts theactuator 1130 and a lug configuration 1132 for use in conjunction withthe mechanism 1106 for opening or deploying the cutting member 1108. Theactuator 1130 and the lug configuration 1132 are also further describedbelow. In addition, FIG. 8a depicts a hole 1134 through the cuttingmember 1108 that is adapted to accommodate the guidewire 1114 while thecutting member 1108 is in its closed position. FIG. 8b depicts adetailed view of the cutting member 1108 in its closed position.

FIG. 8c depicts a further detailed view of the drill bit 1102, thetubular shaft 1103, and the outer tubular shaft 1104, as well as analternative embodiment 1108 a of the cutting member in its fullydeployed position. FIG. 8c further depicts a hole 1134 a (see also FIG.13c ) through the cutting member 1108 a that is adapted to accommodatethe guidewire 1114, thereby securing the cutting member 1108 a in itsdeployed position.

FIG. 9a depicts a detailed view of the outer tubular shaft 1104 and themechanism 1106, as well as a detailed view of various components withina mechanism housing 1156 (see also FIG. 15), including the tab 1136located at the proximal end of the tubular shaft 1104, the compressionspring 1138, the cam wheel 1140, and the drive link 1142 interconnectingthe cam wheel 1140 and the bushing 1144. FIG. 9b depicts an explodedview of the various components within the mechanism housing 1156,further including the actuator 1130 connectable between the cuttingmember 1108 and the bushing 1144.

As described above with reference to FIGS. 3a and 3b , a surgeon canpush or slide the outer tubular shaft 1104 toward the mechanism 1106 inthe direction indicated by the directional arrow 1120 to cause themechanism 1106 to open or deploy the cutting member 1108 in a singlemanual motion. As shown in FIGS. 10a and 10b , as the outer tubularshaft 1104 is pushed toward the mechanism 1106, the tab 1136 comes incontact with the cam wheel 1140, causing the cam wheel 1140 to rotate inthe counter clockwise (CCW) direction and compressing the compressionspring 1138 (see FIG. 10b ). As shown in FIGS. 10b and 11a , as the camwheel 1140 rotates in the CCW direction and the compression spring 1138becomes increasingly compressed, the drive link 1142 moves the bushing1144 toward the distal end of the tubular shaft 1103, thereby causingthe actuator 1130 to open or deploy the cutting member 1108.

Once the compression spring 1138 is fully compressed and the cuttingmember 1108 is fully deployed (see FIG. 11a ), the surgeon can graduallyrelease the outer tubular shaft 1104 to allow the compression spring1138 to push the tubular shaft 1104 against the cutting member 1108 (seeFIG. 11b ), preventing the cutting member 1108 from moving from itsdeployed position.

As shown in FIGS. 12a and 12 b, to move the cutting member 1108 from itsopened or deployed position back to its closed position, the surgeon canagain push or slide the outer tubular shaft 1104 in the directionindicated by a directional arrow 1122 (see FIG. 12b ) to partiallycompress the compression spring 1138 as well as partially expose thetubular shaft 1103, and then push the bushing 1144 toward the mechanism1106 to rotate the cam wheel 1140 in the clockwise (CW) direction (seeFIG. 12b ), thereby causing the actuator 1130 to move the cutting member1108 to its closed position.

FIGS. 13a -16 illustrate various exemplary aspects relating to theoperation and assembly of the disclosed retro guidewire reamer 1100. Asshown in FIG. 13 a, the lug configuration 1132 (see also FIG. 8a )includes one or more internal lugs 1132.1 on the cutting member 1108that are configured to slide over corresponding external lugs 1132.2 onthe tubular shaft 1103. As shown in FIG. 13b , the actuator 1130 isconfigured to snap into a side hole 1146 formed in the cutting member1108. FIG. 13c depicts the alternative embodiment 1108 a of the cuttingmember 1108, including the holes 1134 and 1134 a adapted to accommodatethe guidewire 1114 while the cutting member 1108 a is in its closed andopened or deployed positions, respectively.

As shown in FIG. 14 a, the actuator 1130 is configured to slide into aslot hole 1145 formed in the bushing 1144. As shown in FIG. 14b , thedrive links 1142 are configured slide into holes 1148, 1150 formed itthe bushing 1144 and the cam wheel 1140, respectively. As shown in FIG.15, at least one hub 1152 on the cam wheel 1140 is configured to slideinto at least one corresponding groove slot 1154 formed in the mechanismhousing 1156. As shown in FIG. 16, at least one cap screw 1158 can beemployed to secure a housing cover 1160 to the mechanism housing 1156.Further, at least one button head screw 1162 can be employed to securethe cam wheel 1140, as well as the various components attached to thecam wheel 1140, within the mechanism housing 1156. In addition, at leastone set screw 1164 can be employed to secure the mechanism housing 1156to a portion of a drill 1166.

FIGS. 17a-19b depict various exemplary aspects relating to analternative embodiment 11700 of the retro guidewire reamer 1100. Asshown in FIG. 17a , the retro guidewire reamer 11700 includes a drillbit 11702, an elongated outer tubular shaft 11704, and one or morecutting members 11708 (e.g., 1 or 2 cutting members). Like the retroguidewire reamer 1100, the retro guidewire reamer 11700 can beadvantageously used with a guidewire 11714 (e.g., a 2.4 mm guidewire, orany other suitable guidewire or guide pin) for more accurate bone tunnelplacement during arthroscopic ligament reconstruction surgery, such asACL reconstruction surgery.

As shown in FIGS. 19a and 19 b, the cutting members 11708 are attachedto the outer tubular shaft 11704 by a ball and socket connection 11770,11772. The cutting members 11708 are configured to move axially with theouter tubular shaft 11704, and to rotate via the ball and socketconnection 11770, 11772. The ball and socket connection 11770, 11772 isintegrated into the cutting members 11708 and the outer tubular shaft11704, respectively, advantageously providing a “pin-less” design. Each“male” ball (see reference numeral 11770) is integrated into one of thecutting members 11708, and each “female” socket (see reference numeral11772) is integrated into the outer tubular shaft 11704. Furtherembodiments of the retro guidewire reamer 11700 may employ at least onepin (not shown) to connect the cutting members 11708 to the outertubular shaft 11704.

During an arthroscopic procedure, a surgeon can push or slide the outertubular shaft 11704 toward the drill bit 11702 to cause the cuttingmembers 11708 to impinge against a stop on the drill bit 11702 and torotate outward, thereby opening or deploying the cutting members 11708in a single manual motion. The outer tubular shaft 11704 disposedagainst the drill bit 11702 prevents the cutting members 11708 frommoving from their opened or deployed positions (FIGS. 17b and 17d ). Thesurgeon can subsequently push the outer tubular shaft 11704 away fromthe drill bit 11702 to cause the cutting members 11708 to rotate inwardback to their closed positions (see FIGS. 17a and 17c ).

To facilitate assembly of the retro guidewire reamer 1700, an assemblyslot 11774 (see FIG. 18) can be provided to allow the cutting members11708 to be fully inserted into the inner diameter of the retroguidewire reamer 11700, and to allow the outer tubular shaft 11704 to beadvanced to the proper location for alignment of the ball and socketconnection 11770, 11772. Once the female socket 11772 is aligned withthe assembly slot 11774, the cutting members 11708 can be rotatedoutward until the male ball 11770 resides within the female socket11772. At that point, the outer tubular shaft 11704 with the cuttingmembers 11708 attached thereto can be advanced distally beyond theassembly slot 11774.

FIGS. 20a and 20b depict a further illustrative embodiment of anexemplary retro guidewire reamer 2100, in accordance with the presentapplication. As shown in FIGS. 20a and 20 b, the retro guidewire reamer2100 includes a drill bit 2102 having a tubular (cannulated) shaft 2103,at least one cutting member 2108 operatively coupled near a distal endof the tubular shaft 2103, an elongated outer tubular shaft 2104, aretro drive bushing 2172, a retro lock knob 2174, a retro lock bushingring 2176, and a depth slide 2180. FIG. 20a further depicts a detailedview of the drill bit 2102, the tubular shaft 2103, and the outertubular shaft 2104 disposed over a guidewire 2114. FIG. 20b furtherdepicts a detailed view of the drill bit 2102, the tubular shaft 2103,the outer tubular shaft 2104, and the cutting member 2108 in its fullyopened or deployed position. The retro guidewire reamer 2100 can beadvantageously used with the guidewire 2114 (e.g., a 2.4 mm guidewire,or any other suitable guidewire or guide pin) for more accurate bonetunnel placement during arthroscopic ligament reconstruction surgery,such as AOL reconstruction surgery.

FIGS. 21a and 21b depict various components of the disclosed retroguidewire reamer 2100, including the drill bit 2102, the tubular shaft2103, the cutting member'2108, the outer tubular shaft 2104, the retrodrive bushing 2172, the depth slide 2180, a retrograde actuator 2130,the retro lock knob 2174, and the retro lock bushing ring 2176. Theretro lock knob 2174 can have a pin or projection configured to engage ahole 2178 (see FIG. 21b ) in the tubular shaft 2103, and to make contactwith the guidewire 2114 disposed in the tubular shaft 2103. During use,the retro drive bushing 2172 and the retrograde actuator 2130 cooperateto move the cutting member 2108 from a closed position to its opened ordeployed position, and vice versa. Further, during use, the retro lockknob 2174 and the retro lock bushing ring 2176 cooperate to secure theguidewire 2114 within the tubular shaft 2103, and to stabilize andstrengthen the guidewire 2114 the tubular shaft 2103, and the cuttingmember 2108 as a unit, as further described herein.

FIGS. 22a-22c depict additional views of the retro guidewire reamer 2100of FIGS. 20a and 20b , including the drill bit 2102, the tubular shaft2103, the cutting member 2108, the outer tubular shaft 2104, the retrolock knob 2174, the retro lock bushing ring 2176, and the retro drivebushing 2172. As shown in FIG. 22a , the tubular shaft 2103 isconfigured to be disposed over the guidewire 2114. As shown in FIG. 22b, once the guidewire 2114 is at least partially retracted within thetubular shaft 2103, the retro drive bushing 2172 can be moved along thecuter tubular shaft 2104 toward the distal end of the tubular shaft2103, causing the retrograde actuator 2130 to move the cutting member2108 to its deployed position.

As shown in FIG. 22 c, while the cutting member 2108 is being moved toits fully deployed position, the guidewire 2114 can twist within thetubular shaft 2103 and become engaged with and/or locked into thecutting member 2108. In one embodiment, the guidewire 2114 can includeat least one helix spline 2170 (see FIGS. 20 a, 22 a, and 22 c-22 e), orany other suitable structural feature (e.g., a flute, a slot, a thread),configured to engage with and/or lock into the cutting member 2108 asthe guidewire 2114 twists (or is twisted by a user) within the tubularshaft 2103. Once the cutting member 2108 is in its fully deployedposition, the retro lock knob 2174 can be rotated (e.g., clockwise) tocause the pin or projection to engage the hole 2178 and make contactwith the guidewire 2114 disposed in the tubular shaft 2103, therebysecuring, stabilizing, and strengthening the guidewire 2114, the tubularshaft 2103, and the cutting member 2108 as a unit.

FIG. 22d depicts a detailed view of the drill bit 2102, the tubularshaft 2103, the outer tubular shaft 2104, and the cutting member 2108 inits fully deployed position. While the cutting member 2108 is in itsfully deployed position, the helix spline 2170 (or any other suitablestructural feature of the guidewire 2114) can engage with and/or lockinto the cutting member 2108. In one embodiment, the helix spline 2170can engage with and/or lock into a tab 2182 formed in the cutting member2108, as shown in FIG. 22e . FIG. 22d further depicts the retrogradeactuator 2130, as well as a lug configuration 2132, for use inconjunction with the retro drive bushing 2172 for deploying the cuttingmember 2108. FIG. 22d also depicts a hole 2134 through the cuttingmember 2108 that is adapted to accommodate the guidewire 2114 while thecutting member 2108 is in its closed position. FIG. 22f depicts adetailed view of the cutting member 2108 in its closed position, aplurality of flutes 2102 a formed on the drill bit 2102, and a hole 2147through the cutting member 2108 that is adapted to accommodate theguidewire 2114 while the cutting member 2108 is in its deployed (oropened) position. In one embodiment, the hole 2147 through the cuttingmember 2108 is adapted to receive the helix spline 2170 of the guidewire2114, which, in conjunction with the retro lock knob 2174, can providefurther support and stabilization to the cutting member 2108 in itsdeployed position, while securing the guidewire 2114, the tubular shaft2103, and the cutting member 2108 as a unit.

FIGS. 23a-23m illustrate an exemplary mode of operating the retroguidewire reamer 2100 of FIGS. 20a and 20 b. In this mode of operation,a surgeon can use a guide (not shown) to establish a desired path forthe guidewire 2114 through femoral bone 2116 (see FIG. 23a ). Forexample, the guide may be a pinpoint guide, or any other suitable guide.The surgeon places the guidewire 2114 along the desired path and removesthe guide. The surgeon then obtains a measure straw 2115 that issubstantially the same length as the guidewire 2114 (see FIG. 23b ). Thesurgeon places the measure straw 2115 against the femoral bone 2116, andcuts the measure straw 2115, as desired and/or required, at its proximalend (see FIG. 23c ).

Next, the surgeon determines the size of a primary bone tunnel 2112 (seeFIGS. 23k-23m ), as well as the size of a counter bore 2110 (see FIGS.23k-23m ) through the femoral bone 2116 appropriate to fit a replacementtendon graft, using any suitable technique known in the art. Using thedrill bit 2102 appropriately sized to create the primary bone tunnel2112 (e.g., the drill bit 2102 can be a 4.5 mm drill bit or any othersuitable drill bit), the surgeon uses a power drill (not shown) to drillthe bone tunnel 2112 through the femoral bone 2116 over the guidewire2114 from the outside in (see FIGS. 23d and 23e ). The surgeon then atleast partially retracts the guidewire 2114, and moves the retro drivebushing 2172 along the outer tubular shaft 2104 toward the distal end ofthe tubular shaft 2103, causing the retrograde actuator 2130 to move thecutting member 2108 to its deployed position (see FIGS. 23f and 23g ).While the cutting member 2108 is being moved to its fully deployedposition, the guidewire 2114 twists within the tubular shaft 2103 as thehelix spline 2170 becomes engaged with and/or locks into the tab 2182(see FIG. 22e ) of the cutting member 2108 (see FIG. 23h ). Once thecutting member 2108 is in its fully deployed position, the surgeonrotates (e.g., clockwise) the retro lock knob 2174 to secure andstabilize the guidewire 2114, the tubular shaft 2103, and the cuttingmember 2108 together as a unit (see FIG. 23i ).

Next, the surgeon places the depth slide 2180 against a lateral side ofthe femoral bone 2116 to determine the length of the counter bore 2110(see FIG. 23j ). Alternatively, instead of the depth slide 2180, a depthstraw (not shown) may be employed for determining the length of thecounter bore 2110. The surgeon then uses the power drill with thedeployed cutting member 2108 to create the counter bore 2110 through thefemoral bone 2116 in a retrograde manner (see FIG. 23k ). Once thecounter bore 2110 is drilled, the surgeon rotates (e.g., counterclockwise) the retro lock knob 2174 to release the guidewire 2114 fromwithin the tubular shaft 2103, untwists the guidewire 2114 within thetubular shaft 2103 to disengage the helix spline 2170 from the cuttingmember 2108, and moves the retro drive bushing 2172 along the outertubular shaft 2104 toward the retro lock knob 2174 to cause theretrograde actuator 2130 to move the cutting member 2108 from itsdeployed (opened) position to its closed position, allowing the retroguidewire reamer 2100 to be withdrawn through the primary bone tunnel2112 created by the drill bit 2102 (see FIGS. 23l and 23m ).

It is noted that, in the exemplary mode of operation described above,the counter bore 2110 may be drilled along the axis of the primary bonetunnel 2112, or at a predetermined angle to the primary bone tunnelaxis. It is further noted that the retro guidewire reamer 2100 iscannulated to allow fluid to pass through the tubular shaft 2103 and/orthe outer tubular shaft 2104 during use, thereby clearing out any softtissue that may potentially block the deployment of the cutting member2108.

Having described the above exemplary embodiment of the retro guidewirereamer 2100, other alternative embodiments or variations may be made.For example, the bone tunnel 2112 may be drilled through the femoralbone 2116 over the guidewire 2114 with the distal tip of the retroguidewire reamer 2100 enclosed. The counter bore 2110 may then bedrilled after pivoting, rotating, or otherwise moving the cutting member2108 to its deployed position.

FIG. 24 depicts another illustrative embodiment of an exemplary retroguidewire reamer 3100 for creating tunnels through bone tissue duringarthroscopic ligament reconstruction surgery, in accordance with thepresent application. As shown in FIG. 24, the retro guidewire reamer3100 includes a drill bit 3101 having a tubular (cannulated) shaft 3102,and a cutting member 3104 configured as a small hollow segment. Thecutting member 3104 is pivotally, rotatably, or otherwise movablycoupled at a distal end of the cannulated shaft 3102. The retroguidewire reamer 3100 is operative to drill a tunnel through bone over aguidewire 3106 in an antegrade manner, and to drill a counter borethrough the bone over the guidewire 3106 in a retrograde manner. Theretro guidewire reamer 3100 further includes a lock screw 3108 forlocking the guidewire 3106 in place, as needed, during use. As furthershown in FIG. 24, the guidewire 3106 can have a pointed distal end 3106a.

FIG. 25 depicts a detailed view of the retro guidewire reamer 3100 ofFIG. 24 in a configuration for drilling a tunnel through bone over theguidewire 3106 in an antegrade manner. As shown in FIG. 25, the cuttingmember 3104 is pivotally coupled, by a pair of pivot pins 3105 a at adistal end of the cannulated shaft 3102 in a first position where itscentral axis 3107 is coincident with the longitudinal axis 3109 of theshaft 3102. The cutting member 3104 has a tubular (cannulated) sidewall3111 with sharpened edges 3104.1 at a forward circumferential endthereof.

FIG. 26 is another detailed view of the retro guidewire reamer 3100 ofFIG. 24 in a configuration for drilling a counter bore through bone overthe guidewire 3106 in a retrograde manner. As shown in FIG. 26, thecutting member 3104 is pivotally, rotatably, or otherwise movablycoupled at the distal end of the cannulated shaft 3102 such that it canpivot, rotate, or otherwise move from the first position where itscentral axis 3107 was coincident with the longitudinal axis 3109 of theshaft 3102 (see FIG. 25), to a second position where its central axis3107 is disposed at an angle θ to the longitudinal axis 3109 of theshaft 3102. The cannulated sidewall 3111 of the cutting member 3104 alsohas sharpened edges 3104.2 on an outside surface thereof.

The disclosed retro guidewire reamer 3100 will be further understoodwith reference to the following illustrative example, and FIGS. 27-31.In this example, the retro guidewire reamer 3100 is employed in anarthroscopic surgical procedure to drill a tunnel 3402 (see FIG. 27)through femoral bone 3400 over the guidewire 3106 in an antegrademanner, and to drill a counter bore 3802 (see FIG. 30) through thefemoral bone 3400 over the guidewire 3106 in a retrograde manner. First,a surgeon establishes a desired path 3401 through the femoral bone 3400for the guidewire 3106 using a guide (not shown), places the guidewire3106 along the path 3401, and removes the guide. With the cannulatedshaft 3102 and the cutting member 3104 in the first position (see FIG.25) placed over the guidewire 3106, the surgeon uses the retro guidewirereamer 3100 to drill the tunnel 3402 through the femoral bone 3400 overthe guidewire 3106 from the outside in, in an antegrade manner. In thisexample, the surgeon drills the bone tunnel 3402 using the sharpenededges 3104.1 at the forward circumferential end of the cutting member3104.

Next, the surgeon retracts the guidewire 3106, causing its pointeddistal end 3106 a to be withdrawn inside the cannulated shaft 3102 sothat it is no longer engaged with the cutting member 3104 and blockingor otherwise preventing the cutting member 3104 from movement (see FIG.28). Such retraction of the guidewire 3106 allows the cutting member3104 to pivot, rotate, or otherwise move from the first posit on whereits central axis 3107 was coincident with the shafts longitudinal axis3109 (see FIG. 25), to the second position where its central axis 3107is disposed at the angle θ to the shaft's longitudinal axis 3109 (seeFIGS. 26 and 29). The surgeon then advances the guidewire 3106, causingpointed distal end 3106 a to pass through the cannulated shaft 3102 to aposition beyond the pivot coupling of the cutting member 3104 and theshaft 3102, and to block or otherwise prevent any further movement ofthe cutting member 3104 (see FIG. 29). The surgeon can now lock theguidewire 3106 to the cannulated shaft 3102 using the lock screw 3108(see FIG. 31), thereby securing the cutting member 3104 in the angledsecond position. With the cannulated shaft 3102 placed over theguidewire 3106 and the cutting member 3104 in the second position, thesurgeon can drill the counter bore 3802 (see FIG. 30) through thefemoral bone 3400 over the guidewire 3106 in a retrograde manner, usingthe sharpened edges 3104.2 on the outside surface of the cuttingmember's sidewall 3111.

Having described the above exemplary embodiment of the disclosed retroguidewire reamer 3100, other alternative embodiments or variations maybe made. For example, it was described herein that a surgeon can drill abone tunnel over the guidewire 3106 in an antegrade manner using thesharpened edges 3104.1 at the forward circumferential end of the cuttingmember 3104, and drill a counter bore through the bone over theguidewire 3106 in a retrograde manner using the sharpened edges 3104.2on the outside surface of the cutting member's sidewall 3111. In analternative embodiment 3900 of the retro guidewire reamer (see FIG. 32)sharpened edges at a forward circumferential end of a tubular(cannulated) shaft 3902 can be used to drill a bone tunnel over aguidewire in an antegrade manner.

FIG. 32 depicts the retro guidewire reamer 3900, which includes a drillbit having the cannulated shaft 3902 with a longitudinal axis 3909, anda cutting member 3904 configured as a small hollow segment with acentral axis 3907. The cutting member 3904 is pivotally coupled by pivotpins 3905 adjacent a distal end of the cannulated shaft 3902 such thatit can rotate from a first position where its central axis 3907 iscoincident with the longitudinal axis 3909 of the shaft 3902, to asecond position where its central axis 3907 is disposed at an angle γ tothe longitudinal axis 3909 of the shaft 3902. The cannulated shaft 3902has sharpened edges 3902.1 at a forward circumferential end thereof fordrilling a bone tunnel over a guidewire 3906 in an antegrade manner, andthe cutting member 3904 has a sidewall with sharpened edges 3904.1 on anoutside surface thereof for drilling, a counter bore over the guidewire3906 in a retrograde manner.

It is noted that, after the cutting member 3904 is rotated to the secondposition where its central axis 3907 is disposed at the angle γ to thelongitudinal axis 3909 of the shaft 3902, a surgeon can advance theguidewire 3906, causing its pointed distal end 3906 a to pass throughthe cannulated shaft 3902 to a position beyond the pivot coupling of thecutting member 3904 and the shaft 3902, and to block or otherwiseprevent any further rotation or movement of the cutting member 3904 (seeFIG. 32). An opening is provided in the portion of the cutting member'ssidewall disposed within the cannulated shaft 3902 to allow the pointeddistal end 3906 a of the guidewire 3906 to pass through the cuttingmember 3904 when it is disposed in the second position (see FIG. 32). Toallow the cutting member 3904 to pivot, rotate, or otherwise move fromthe second position back to the first position, where its central axis3997 is coincident with the longitudinal axis 3909 of the shaft, thesurgeon can retract the guidewire 3906, causing its pointed distal end3906 a to be withdrawn inside the cannulated shaft 3902 so that it is nolonger engaged with the cutting member 3904 and blocking or otherwisepreventing the cutting member 3904 from rotation or movement.

A method of operating the disclosed retro guidewire reamers 3100, 3900for creating tunnels through bone tissue during arthroscopic ligamentreconstruction surgery is described below with reference to FIG. 33. Asdepicted in block 31002, a retro guidewire reamer is provided includinga drill bit having a cannulated shaft, and a cutting member configuredas a small hollow segment, in which the cutting member is pivotally,rotatably or otherwise movably coupled at a distal end of the cannulatedshaft, allowing the cutting member to pivot, rotate, or otherwise movefrom a first position where its central axis is coincident with alongitudinal axis the shaft, to a second position where its central axisis disposed at an angle to the longitudinal of the shaft. As depicted inblock 31004, with the cutting member disposed in the first position, atunnel is drilled through the bone over a guidewire in an antegrademanner. As depicted in block 31006, with the cutting member disposed inthe second position, a counter bore is drilled through the bone over theguidewire in a retrograde manner.

It will be appreciated by those of ordinary skill in the art thatmodifications to and variations of the above-described apparatus andmethods may be made without departing from the inventive conceptsdisclosed herein. Accordingly, the invention should not be viewed aslimited except as by the scope and spirit of the appended claims.

What is claimed is:
 1. A method of performing an arthroscopic surgicalprocedure, comprising: disposing a surgical instrument including acannulated shaft over a guidewire, the surgical instrument furtherincluding: a cutting member movably disposed adjacent a distal end ofthe cannulated shaft, the cutting member being configured to movebetween a closed position where a central axis thereof is coincidentwith a longitudinal axis of the cannulated shaft, and a deployedposition where the central axis of the cutting member is disposed at anangle to the longitudinal axis of the cannulated shaft; and a drivebushing configured for axial movement along an outer surface of thecannulated shaft for moving the cutting member between the closedposition and the open position; while the cutting member is in theclosed position, drilling a tunnel through bone over the guidewire in anantegrade manner; using the drive bushing, moving the cutting memberfrom the closed position to the deployed position; and while the cuttingmember is in the deployed position: engaging the cutting member with theguidewire to prevent movement of the cutting member from the deployedposition; and drilling, by the cutting member, a counter bore throughthe bone over the guidewire in a retrograde manner.
 2. The method ofclaim 1 wherein the cutting member has a cannulated sidewall withsharpened edges at a forward circumferential end thereof, and whereinthe drilling of the tunnel includes drilling the tunnel through the boneover the guidewire using the sharpened edges at the forwardcircumferential end of the cannulated sidewall of the cutting member. 3.The method of claim 1 wherein the cutting member has a cannulatedsidewall with sharpened edges on an outside surface thereof, and whereinthe drilling of the counter bore includes drilling the counter borethrough the bone over the guidewire using the sharpened edges on theoutside surface of the cannulated sidewall.
 4. The method of claim 1further comprising: while the cutting member is in the closed position,retracting the guidewire within the cannulated shaft to allow thecutting member to move from the closed position where its central axisis coincident with the longitudinal axis of the cannulated shaft, to thedeployed position where its central axis is disposed at the angle to thelongitudinal axis of the cannulated shaft.
 5. The method of claim 1further comprising: while the cutting member is in the deployedposition, advancing the guidewire within the cannulated shaft to preventmovement of the cutting member from the deployed position during use. 6.The method of claim 1 wherein said drilling the tunnel through bone overthe guidewire in an antegrade manner comprises drilling the tunnel withthe distal end of the cannulated shaft, the distal end of the cannulatedshaft comprising a drill bit.
 7. The method of claim 1 furthercomprising securing the guidewire within the cannulated shaft with alocking mechanism, the locking mechanism being included in the drivebushing.
 8. The method of claim 1 wherein the at least one cuttingmember defines a hole through the cutting member adapted to accommodatepassage of the guidewire therethrough least while in the deployedposition.
 9. The method of claim 8 wherein the hole is configured to beengageable with a structural feature of the guidewire while in thedeployed position.